Burglar-alarm



(NoModeL) A. I. R. ARNDT.

Burglar Alarm.

No. 235,118. Patented Dec. 7,18 80.

N. PETERS, FHOTO-LITHOGRAFH UNITED STATES ALBERT F. R. ARNDT, OFDETROIT, MICHIGAN.

BU RGLAR-ALARM.

SPECIFICATION forming part of Letters Patent No. 235,118, dated December'7, 1880.

Application filed October 8, 1880. (No model.)

To all whom it may concern:

Be it known that I, ALBERT F. R. ARNDT, of Detroit, in the county ofWayne and State of Michigan, have invented an Improvement inBurglarAlarms, of which the following is a specification.

The nature of my invention relates to certain new and usefulimprovements in the construction and operation of that class of devicesto be attached to doors, windows, &c., for exploding detonating caps,and technically termed burglar-alarms.

The invention consists in the peculiar construction, arrangement, andoperation of the various parts, as more fully hereinafter described.Figure 1 is a perspective view of my improved device as attached to adoor frame ready to be actuated by the opening of the door. Fig. 2 is arear perspective "iew of the same detached. Fig. 3 is a perspective ofthe same attached to a handle.

In the accompanying drawings, which form a part of this specification, Arepresents the shell, cast with an open back, and with an opening, a,through the front for the purpose of inserting the detonating cap or acartridge. A pointed lug, b, is cast on the rear face, and this, withthe thumb-screw c, secures the device to the door-frame.

B is the nipple, which is preferably made removable for the insertion ofa cartridge, and as shown in dotted lines in Fig. 3.

G isthe hammer, secured to the lower end of a rod, D, which passesthrough the actuating coil-spring E.

The bar at holds the rod and hammer in place in the shell and forms theupper point of resistance to the spring, the opposite end of whichimpinges against the head of the hammer.

F is a spindle pivotally secured to the hammer, and, passing through theslot 0 in the front of the shell, terminates in a handle, h. Thisspindle will allow the handle to be turned in either direction, so thatthe device may be operative on a right or left hand door.

By means of the handle the hammer is withdrawn, compressing the spring,and then by turning the handle to one side or the other the spindle willengage with one of the notches,

, k, in the shell at the upper end of the slot 0,

and this operation locks the hammer in the withdrawn position. Thehandle being turned so as to project when the device is secured to theside of a door-frame beyond the edge of the door, any attempt to opensaid door will throw the spindle out of its engagement with the notch,thereby relieving the spring, which will force the hammer to strike thecap with sufficient force to explode it.

As this device is especially adapted for use by travelers, it maybeemployed as a pistol. by attaching it to a handle, H, and the nipple maybe removed and a shell-cartridge inserted in the cavity a, when thedevice will be found to be a very efficient'implement for defense atshort range, the finger of the operator being used to trip the detent.

I am aware that a reversible detent secured to a hammer operated by aspring with two recesses on each side of a vertical slot in the case forthe reception of the detent has heretofore been employed, and Itherefore lay no claim to such construction, which differs from mine inthat the vertical slot is not arranged centrally in the face of theshell, and that the notches are not arranged on opposite sides of theedges of the shell, and the device cannot be applied at will to a rightor left hand door, the device in the construction disclaimed beingadapted to operate on a right-hand door only in both opening and closingsuch door.

What I claim as my invention is- 1. The combination, with thecentrally-slotted shell A, provided with recesses k k, arranged onopposite sides of the edges of the shell, of the rod D, hammer O,trigger F h, pivotally secured to the hammer, and spiral spring E,whereby the alarm may be applied to a right or left hand door,substantially as described.

2. The combination, with the handle H, of the open-back shell A,provided with the slot 0, having recesses is k, arranged on oppositesides of its edges, opening a, cartridgecavity a, hammer 0, rod 1),core-spring E, swiveled trigger F h, and removable nipple B,substantially as described, and for the purpose set forth.

ALBERT F. R. ARNDT.

Witnesses:

H. S. SPRAGUE, A. WAHL.

